1. Field of the Invention
The present invention relates to an endoscope light source apparatus to which an endoscope is to be connected.
2. Description of the Related Art
In recent years, in endoscopy, besides normal light observation utilizing white light, specific light observation that improves visibility of a living body by utilizing light in a narrow wavelength band is being carried out. As a light source that generates the specific light, use of laser light has received attention because of, in particular, its high narrow-band properties, and specific light of various combinations is being developed. Jpn. Pat. Appln. KOKAI Publication No. 2013-013560 discloses, as an example, a constitution that combines the optical path of laser light with the optical path of white light by a reflecting plate to reflect laser light arranged in the optical path of white light in order to enable observation of oxygen saturation of a surface blood vessel. This constitution enables even conventionally-used endoscopes to use novel specific light. In general, in conventional endoscopes, light is guided to the distal end by a bundle fiber, and emitted as illumination light after light distribution is adjusted by a lens, etc.
In contrast, an endoscope that uses laser light sources, not a conventional light source such as a lamp or light emitting diodes, even in normal observation, has been developed in recent years. Such an endoscope can produce white light or any specific light by combinations enabled by using a single optical fiber as a light guide and exciting a phosphor mounted on a distal end portion of the endoscope, and can perform normal observation and specific light observation only by the laser light sources. In the endoscope using a single optical fiber, since the fiber is the single optical fiber, a smaller diameter of the endoscope can be provided and a lower-power endoscope system can be also achieved.